Haul-out behaviour of walruses (Odobenus rosmarus) monitored by camera stations - potential impacts of tourist visitations

Abstract

The rapid growth of tourism in Polar Regions stimulates a need for investigating potential impacts on targeted species and sensitive areas, such as walrus (Odobenus rosmarus) haul-out sites. This study examines effects of tourist visitations on haul-out dynamics and site use by walruses in Svalbard, Norway. Camera stations were established at five traditional walrus haul-out sites that experience variable levels of tourist visitation. The cameras took one photograph each hour, throughout June-November from 2007-2015 (3 sites) and 2010-2015 (2 sites). A total of 66,365 images were analysed in this study. The number of walruses on shore, and % sea ice cover was estimated for each image. Additionally, the presence/absence of tourists, boats and polar bears (Ursus maritimus) was recorded. A log-linear regression model was run on residuals from an ARIMA model fitted to the time series. Site use by walruses was sometimes restricted by sea ice cover, but walruses were also absent (or present rarely) at some sites, despite a lack of sea ice. Tourists and boats did not disturb walrus haul-out behaviour significantly (p>0.05) at any of the study sites. Additionally, most polar bear visits were not associated with any detectable disturbance. However, polar bears did significantly disturb walrus herds at Andréetangen (p=3.47^-5) and Storøya (p=1.52^-5) in some years. These disturbances were likely associated with predation attempts on calves. Given the increasing number of calves in Svalbard, and the high numbers of bears on shore during increasingly longer ice-free seasons, such disturbances are likely to increase in the future.